Health officials are alerting travelers about a significant outbreak of chikungunya virus in southern China. The Centers for Disease Control and Prevention (CDC) issued a travel warning on Friday, highlighting the situation in Guangdong Province, where over 7,000 cases have been confirmed since June 2025. The outbreak has been exacerbated by monsoon flooding, which has created favorable conditions for mosquito breeding.

Chikungunya is a mosquito-borne virus primarily transmitted by the Aedes aegypti mosquito. Dr. Jeffrey Silvers, medical director for Pharmacy & Infection Control at Sutter Health, described the virus as "very unpleasant" and noted that it typically causes severe pain. Symptoms usually appear within three to seven days after a person is bitten by an infected mosquito.

Dr. John Swartzberg, a clinical professor emeritus at UC Berkeley's School of Public Health, explained that chikungunya is not a new disease. It has been recognized for decades, with cases reported in regions such as the Caribbean, Mexico, and Central and South America. The European CDC reported approximately 240,000 global infections this year.

In the United States, there have been no locally acquired cases of chikungunya since 2019. However, Dr. Swartzberg warned that climate change could lead to an increase in cases as the range of the mosquitoes expands. Aedes aegypti mosquitoes were detected in Santa Clara County a few years ago, raising concerns about local transmission.

Dr. Taylor Kelly, who works with the vector control district in Santa Clara County, emphasized the importance of monitoring these mosquitoes. "It's a very serious public nuisance and it's also able to vector these diseases such as dengue, chikungunya, and Zika virus that are threats to public health," she said.

Travelers to affected areas are advised to take precautions. Dr. Todd Ellerin, chief of infectious disease at South Shore Health in Massachusetts, recommended wearing long sleeves and pants, using insect repellent containing DEET, and employing mosquito netting for infants.

Common symptoms of chikungunya include sudden-onset high fever, severe joint pain, muscle pain, headache, fatigue, and skin rash. Most individuals recover within seven to ten days, but some may experience lingering symptoms for weeks or months. There is no specific antiviral treatment for chikungunya; care focuses on symptom relief.

Vaccination is available and recommended for travelers visiting areas with active outbreaks. The CDC advises that those spending extended time abroad or laboratory workers handling the virus should also consider vaccination.

As the situation develops, health officials continue to monitor the outbreak and encourage travelers to stay informed about the risks associated with chikungunya.